1. Field of the Invention
The present invention relates to door hinges generally; more particularly, the invention relates to a pin for a door hinge that overcomes the problem of a door's swinging away, under the influence of gravity, from a user's chosen open position for the door to some other position.
2. Background Art
Doors mounted on hinges over wall openings in buildings, cabinetry, motor vehicles, et cetera, tend to develop malfunctions over time. Of particular interest for the present invention are door hinges of the kind that comprise two hinge plates or leaves that are assemblable to form a butt hinge, each hinge leaf having one or more pintle journals or knuckles, wherein the knuckles are complementarily spaced apart so as to be interleaveable on a common axis, and wherein each of the knuckles defines an open chamber for receiving a hinge pin. In the case of doors mounted on two or more such butt hinges that are vertically aligned to permit the door to swing about a vertical axis, the hinges may become misaligned and/or the hinges may become so worn by use that the hinges develop excessive play; in either case, an attempt to leave the door in a desired open position may result in the door's swinging by gravity to some other position.
U.S. Pat. No. 1,900,081 issued to Swerer disclosed an adjustable hinge having a first set of vertically-spaced knuckles attachable by a jamb plate to a door jamb and a second set of vertically-spaced knuckles attachable by a door-engaging plate to a door. The knuckles within each set were concentrically aligned with each other, but the two sets of knuckles were ordinarily positioned out of axial alignment with each other. A hinge pin, preferably of hexagonal transverse cross-section, carried cylindrically-shaped eccentrics such that rotational adjustment of a lower, protruding end of the pin would alter the distance between the door and the jamb.
U.S. Pat. No. 1,908,383 issued to Vice disclosed an adjustable hinge comprising a pair of cooperating hinge plates having interleaved pintle journals that extended into the spaces between the journals. A lower portion of the hinge pin was of non-circular cross-section and adapted to insert into slots or grooves formed in eccentrics. One eccentric was provided for insertion and retention within each of the pintle journals, and each eccentric consisted of a cylindrical body. To install the eccentric pin structure, the hinge plates of a standard butt hinge were separated and the journals reamed out to receive the eccentrics in order to relatively adjust the plates of the hinge and thereby to properly adjust the position of the door within a wall opening.
U.S. Pat. No. 2,533,502 to Philips disclosed a hinge pin that could be employed as a replacement unit for hinge pins already installed. The replacement pin had bearing portions axially aligned to form bearings in the knuckles of one of the hinge leaves; alternately disposed, reduced-diameter crank portions formed on the pin for positioning in the knuckle bores of the companion hinge leaf; and eccentric bushings mounted on the crank portions of the pin. Each bushing was longitudinally split open to permit seating upon a reduced-diameter crank portion of the pin. Means was provided for rotating the pin once it was installed within a hinge, such as a kerf in the head of the pin, rotatable by a coin or screwdriver.
U.S. Pat. No. 4,864,690 to Chen disclosed a butt hinge intended to substantially eliminate the friction that results when two or more hinges on a door become misaligned and to permit up to at least a 5° deviation of the hinge pin in either direction. The hinge mainly comprised a set of hinge butts, a center shaft insertable through the cylinder of the hinge butts and having a ball-shaped part in a mid-portion thereof, and two sets of ball bearings mounted on upper and lower ends of the ball-shaped part to provide a rolling friction between the center shaft and the butts.
U.S. Pat. No. 6,591,450 B2 to Gardner disclosed a door hinge comprising a knuckle with a cylindrical opening and having a mounting plate for mounting to a door; a mounting bracket for attachment to a door frame and having a pair of apertured flanges spaced apart to receive the knuckle therebetween; and a hinge pin insertable through the flange apertures and through the knuckle opening when the apertures and the knuckle opening were coaxially aligned, thereby to connect the knuckle and attached door to the mounting bracket. The pin had an intermediate ball part that fit snugly within the knuckle opening and opposing extended shanks that were fitted freely to permit transverse movement of the shanks within the knuckle opening. Consequently, a door mounted on two or more such hinges could swing freely and without excessive friction even if the hinges were misaligned.
The foregoing references do not adequately address the problem of a waywardly swinging door that is mounted somewhat askew to a door frame by butt hinges. To minimize time, labor and expense, it is desirable to be able to retain the existing butt hinges in position and to replace only the hinge pins with hinge pins that, merely by rotational adjustment of the pins, will introduce just enough friction into the hinges to eliminate the problem. Vince required reaming out the journals to receive his eccentrics. The solutions offered by Swerer, Chen and Gardner would require replacement of the existing butt hinges with their own novel hinges. Phillips teaches replacement of only the hinge pin, but his hinge pin is unnecessarily complicated for the limited purpose addressed by the present invention.